Nuclear magnetic resonance relaxation is used as the primary research tool to investigate the nature of water and water-macromolecule interactions in a variety of systems. The aim of this research is to provide the underlying physical measurements required for an understanding of or an interpretation of similar data obtained from tissue systems in a possibly clinical context. The proposed work includes nmr relaxation studies on all the nuclei of water, (1H, 2H, 17O) and several associated with the protein (1H, 13C) in a variety of chemical and physical environments (crystal, powder, frozen solution, solution). Data will be obtained by pulsed nmr methods, and analysis will include the possibility of cross relaxation between solvent and the semi-solid macromolecule matrix. A short range goal of the research is to understand the detail of the interlay between the water molecule dynamics and the macromolecule or protein dynamics. BIBLIOGRAPHIC REFERENCES: E. Hsi, R. Mason, R. G. Bryant, J. Phys. Chem., 80, 2592 (1976). "Magnetic Resonance Studies of alpha-Chymotrypsin Crystals." E. Hsi, R. G. Bryant J. Phys. Chem., 81, 462 (1977). "Nuclear Magnetic Resonance Relaxation Studies of Carbonic Anhydrase Derivatives in Frozen Solutions."